668 research outputs found

    Magnetic imaging: a new tool for UK national nuclear security.

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    Combating illicit trafficking of Special Nuclear Material may require the ability to image through electromagnetic shields. This is the case when the trafficking involves cargo containers. Thus, suitable detection techniques are required to penetrate a ferromagnetic enclosure. The present study considers techniques that employ an electromagnetic based principle of detection. It is generally assumed that a ferromagnetic metallic enclosure will effectively act as a Faraday cage to electromagnetic radiation and therefore screen any form of interrogating electromagnetic radiation from penetrating, thus denying the detection of any eventual hidden material. In contrast, we demonstrate that it is actually possible to capture magnetic images of a conductive object through a set of metallic ferromagnetic enclosures. This validates electromagnetic interrogation techniques as a potential detection tool for National Nuclear Security applications

    Magnetic Imaging through Metallic Enclosures

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    Security applications may require the ability to image through electromagnetic shields. This is for example the case when trafficking of illicit material involves cargo containers. Thus, suitable detection techniques are required to penetrate a ferromagnetic enclosure. We report on the demonstration of the ability of a system based on electromagnetic interrogation techniques to create magnetic images of metallic objects concealed within metallic enclosures. The penetrating power through single and double ferromagnetic enclosures was investigated. The instrument employs a driver Helmholtz-coil assembly and an array of 20 × 20 sensor coils. The sample objects were imaged via phase variation measurements between the driver and sensor coils, due to inductive coupling between the coils and the sample object

    Industrial bees: the impact of apicultural intensification on local disease 1 prevalence

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.1) It is generally thought that the intensification of farming will result in higher disease prevalences, although there is little specific modelling testing this idea. Focussing on honeybees, we build multi18 colony models to inform how ‘apicultural intensification’ is predicted to impact honeybee pathogen epidemiology at the apiary scale. 2) We used both agent-based and analytical models to show that three linked aspects of apicultural intensification (increased population sizes, changes in population network structure, and increased between-colony transmission) are unlikely to greatly increase disease prevalence in apiaries. Principally this is because even low-intensity apiculture exhibits high disease prevalence. 3) The greatest impacts of apicultural intensification are found for diseases with relatively low R0 (basic reproduction number), however, such diseases cause little overall disease prevalence and therefore the impacts of intensification are minor. Furthermore, the smallest impacts of intensification are for diseases with high R0 values, which we argue are typical of important honeybee diseases. 4) Policy Implications: Our findings contradict the idea that apicultural intensification by crowding honeybee colonies in large, dense apiaries leads to notably higher disease prevalences for established honeybee pathogens. More broadly, our work demonstrates the need for informative models of all agricultural systems and management practices in order to understand the implications of management changes on diseasesBiotechnology & Biological Sciences Research Council (BBSRC

    Centre selection for clinical trials and the generalisability of results: a mixed methods study.

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    BACKGROUND: The rationale for centre selection in randomised controlled trials (RCTs) is often unclear but may have important implications for the generalisability of trial results. The aims of this study were to evaluate the factors which currently influence centre selection in RCTs and consider how generalisability considerations inform current and optimal practice. METHODS AND FINDINGS: Mixed methods approach consisting of a systematic review and meta-summary of centre selection criteria reported in RCT protocols funded by the UK National Institute of Health Research (NIHR) initiated between January 2005-January 2012; and an online survey on the topic of current and optimal centre selection, distributed to professionals in the 48 UK Clinical Trials Units and 10 NIHR Research Design Services. The survey design was informed by the systematic review and by two focus groups conducted with trialists at the Birmingham Centre for Clinical Trials. 129 trial protocols were included in the systematic review, with a total target sample size in excess of 317,000 participants. The meta-summary identified 53 unique centre selection criteria. 78 protocols (60%) provided at least one criterion for centre selection, but only 31 (24%) protocols explicitly acknowledged generalisability. This is consistent with the survey findings (n = 70), where less than a third of participants reported generalisability as a key driver of centre selection in current practice. This contrasts with trialists' views on optimal practice, where generalisability in terms of clinical practice, population characteristics and economic results were prime considerations for 60% (n = 42), 57% (n = 40) and 46% (n = 32) of respondents, respectively. CONCLUSIONS: Centres are rarely enrolled in RCTs with an explicit view to external validity, although trialists acknowledge that incorporating generalisability in centre selection should ideally be more prominent. There is a need to operationalize 'generalisability' and incorporate it at the design stage of RCTs so that results are readily transferable to 'real world' practice

    OMERACT Filter 2.1: Elaboration of the Conceptual Framework for Outcome Measurement in Health Intervention Studies

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    Objective: The Outcome Measures in Rheumatology (OMERACT) Filter 2.0 framework was developed in 2014 to aid core outcome set development by describing the full universe of “measurable aspects of health conditions” from which core domains can be selected. This paper provides elaborations and updated concepts (OMERACT Filter 2.1). Methods: At OMERACT 2018, we discussed challenges in the framework application caused by unclear or ambiguous wording and terms and incompletely developed concepts. Results: The updated OMERACT Filter 2.1 framework makes benefits and harms explicit, clarifies concepts, and improves naming of various terms. Conclusion: We expect that the Filter 2.1 framework will improve the process of core set development

    The response of mental health professionals to clients seeking help to change or redirect same-sex sexual orientation

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    <p>Abstract</p> <p>Background</p> <p>we know very little about mental health practitioners' views on treatments to change sexual orientation. Our aim was to survey a representative sample of professional members of the main United Kingdom psychotherapy and psychiatric organisations about their views and practices concerning such treatments.</p> <p>Methods</p> <p>We sent postal questions to mental health professionals who were members of British Psychological Society, the British Association for Counselling and Psychotherapy, the United Kingdom Council for Psychotherapy and the Royal College of Psychiatrists. Participants were asked to give their views about treatments to change homosexual desires and describe up to five patients each, whom they has treated in this way.</p> <p>Results</p> <p>Of 1848 practitioners contacted, 1406 questionnaires were returned and 1328 could be analysed. Although only 55 (4%) of therapists reported that they would attempt to change a client's sexual orientation if one consulted asking for such therapy, 222 (17%) reported having assisted at least one client/patient to reduce or change his or her homosexual or lesbian feelings. 413 patients were described by these 222 therapists: 213 (52%) were seen in private practice and 117 (28%) were not followed up beyond the period of treatment. Counselling was the commonest (66%) treatment offered and there was no sign of a decline in treatments in recent years. 159 (72%) of the 222 therapists who had provided such treatment considered that a service should be available for people who want to change their sexual orientation. Client/patient distress and client/patient autonomy were seen as reasons for intervention; therapists paid attention to religious, cultural and moral values causing internal conflict.</p> <p>Conclusion</p> <p>A significant minority of mental health professionals are attempting to help lesbian, gay and bisexual clients to become heterosexual. Given lack of evidence for the efficacy of such treatments, this is likely to be unwise or even harmful.</p

    The BIG 2.04 MRC/EORTC SUPREMO Trial: pathology quality assurance of a large phase 3 randomised international clinical trial of postmastectomy radiotherapy in intermediate-risk breast cancer

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    Introduction SUPREMO is a phase 3 randomised trial evaluating radiotherapy post-mastectomy for intermediate-risk breast cancer. 1688 patients were enrolled from 16 countries between 2006 and 2013. We report the results of central pathology review carried out for quality assurance. Patients and methods A single recut haematoxylin and eosin (H&E) tumour section was assessed by one of two reviewing pathologists, blinded to the originally reported pathology and patient data. Tumour type, grade and lymphovascular invasion were reviewed to assess if they met the inclusion criteria. Slides from potentially ineligible patients on central review were scanned and reviewed online together by the two pathologists and a consensus reached. A subset of 25 of these cases was double-reported independently by the pathologists prior to the online assessment. Results The major contributors to the trial were the UK (75%) and the Netherlands (10%). There is a striking difference in lymphovascular invasion (LVi) rates (41.6 vs. 15.1% (UK); p = <0.0001) and proportions of grade 3 carcinomas (54.0 vs. 42.0% (UK); p = <0.0001) on comparing local reporting with central review. There was no difference in the locally reported frequency of LVi rates in node-positive (N+) and node-negative (N−) subgroups (40.3 vs. 38.0%; p = 0.40) but a significant difference in the reviewed frequency (16.9 vs. 9.9%; p = 0.004). Of the N− cases, 104 (25.1%) would have been ineligible by initial central review by virtue of grade and/or lymphovascular invasion status. Following online consensus review, this fell to 70 cases (16.3% of N− cases, 4.1% of all cases). Conclusions These data have important implications for the design, powering and interpretation of outcomes from this and future clinical trials. If critical pathology criteria are determinants for trial entry, serious consideration should be given to up-front central pathology review
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